Stock drinkers have been constructed with tanks insulated with foam or other insulated materials for keeping the water from freezing during the winter months and cool during the summer months. Examples of aminal drinkers having foam plastic insulated walls are shown by Martin in U.S. Pat. No. 3,745,977; Kapplinger in U.S. Pat. No. 4,100,885; and Schafer et al in U.S. Pat. Nos. 4,343,264 and 4,395,974. These animal drinkers have inner and outer plastic walls reinforced with glass fibers. The walls are separately made and secured together. Foam plastic is then injected into the space between the inner and outer walls. This manufacturing procedure is labor intensive and expensive.
Tank-type watering devices have drinking wells closed with a movable covers or lids. The animal raises a lid to provide access to the water in the drinking well. Float valve assemblies are used to automatically maintain the level of the water in the tank. The float valve assemblies are isolated from the drinking wells with baffles that extend downwardly from the inside of the top wall of the watering devices into the water therein. The baffles extend transversely between the side walls of the tank. The baffles act as guides for directing convection circulation of water in the tank.